Nanosys technology triples tablet and smartphone color gamut

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Today’s tablet, laptop, and smartphone TFT LCD displays are predominantly back-lit with Gallium Nitride (GaN) LEDs. GaN LEDs are incredibly power efficient, but they have one major flaw: they produce very blue light. With clever use of phosphor filters, more yellow can be added to make the light look like “daylight”, but the end result is a reduced and very muddy color gamut that’s only around a third of the standard NTSC broadcast gamut. There are other technologies that produce wider gamuts, but at the expense of brightness — which is a no-no, as far as daylight-readable tablet displays go. And then there’s Nanosys with its Quantum Dot Enhanced Film (QDEF).

QDEF is a new phosphor filter that replaces the diffuser filter and is placed between the backlight of an LCD display and the active matrix of pixels. Exact details are slim, but the basic concept of changing-the-spectrum-with-phosphors is the same; Nanoysys’ phosphors are simply better at producing real, broad-spectrum daylight from blue GaN LEDs. Unlike standard phosphors that increase the amount of yellow light, QDEF creates a light that has three very pure bands of red, blue, and green. Presumably this is done with a very fine mesh of red-, green- and blue-emitting phosphors that are close enough together to produce a pure white light. Then, when this white light hits the actual pixels, much brighter and more saturated colors are created.

Unfortunately, because most of us surf the web with low-gamut display, it’s hard to illustrate just how effective the Nanosys QDEF system is. In the image above (QDEF is on the right), you can see that the reds are redder and the greens are greener — and basically, that’s the exact definition of an increased gamut. With low-gamut displays, you might have 5 different shades of red that are lumped together into a single pixel color — but with QDEF, most of those shades will be visually distinguishable. Most users don’t realize just how crippled tablet and smartphone displays are, nor do they realize that the human brain associates color gamut with overall image quality. If you’ve used an old TFT monitor, you’ll appreciate just how far TFT technology has come — but now, imagine if your current display was twice as color-rich. That’s what QDEF can do — and that’s how QDEF might just revolutionize how we browse photos and videos on our portable devices.

The best bit, though, is that QDEF can be implemented in LED LCD displays today, and Samsung and LG Innotek displays with the new technology should be available by the end of the year. Furthermore, QDEF doesn’t increase the final cost of the device, it doesn’t reduce battery life (it actually increases screen brightness slightly), and it doesn’t require a special manufacturing technique. For now, the only real problem that Nanosys faces is volume: it has a high-yield manufacturing process that can cater for tens of thousands of displays, but if it wants to find a home in the iPad 3, the process will have to be scaled up to support tens of millions.